A filtrable virus, identical with that which causes acute lymphocytic choriomeningitis, has been found to cause a disease in white mice.
Naturally infected mice usually show no symptoms, but such animals inoculated intracerebrally with sterile bouillon or other materials develop characteristic symptoms. The same symptoms are produced by intracerebral injection of the virus into mice from a disease-free stock. Guinea pigs are very susceptible and are therefore useful for detecting the virus and for neutralization tests. The disease in both naturally infected and inoculated animals is discussed and the pathological findings given.